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  <div class="section" id="mapping-protocol">
<span id="mapping"></span><h1>Mapping Protocol<a class="headerlink" href="#mapping-protocol" title="Permalink to this headline">¶</a></h1>
<dl class="function">
<dt id="c.PyMapping_Check">
int <code class="descname">PyMapping_Check</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_Check" title="Permalink to this definition">¶</a></dt>
<dd><p>Return <code class="docutils literal"><span class="pre">1</span></code> if the object provides mapping protocol, and <code class="docutils literal"><span class="pre">0</span></code> otherwise.  This
function always succeeds.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_Size">
Py_ssize_t <code class="descname">PyMapping_Size</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_Size" title="Permalink to this definition">¶</a></dt>
<dt id="c.PyMapping_Length">
Py_ssize_t <code class="descname">PyMapping_Length</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_Length" title="Permalink to this definition">¶</a></dt>
<dd><p id="index-0">Returns the number of keys in object <em>o</em> on success, and <code class="docutils literal"><span class="pre">-1</span></code> on failure.  For
objects that do not provide mapping protocol, this is equivalent to the Python
expression <code class="docutils literal"><span class="pre">len(o)</span></code>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_DelItemString">
int <code class="descname">PyMapping_DelItemString</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em>, const char<em>&nbsp;*key</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_DelItemString" title="Permalink to this definition">¶</a></dt>
<dd><p>Remove the mapping for object <em>key</em> from the object <em>o</em>. Return <code class="docutils literal"><span class="pre">-1</span></code> on
failure.  This is equivalent to the Python statement <code class="docutils literal"><span class="pre">del</span> <span class="pre">o[key]</span></code>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_DelItem">
int <code class="descname">PyMapping_DelItem</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*key</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_DelItem" title="Permalink to this definition">¶</a></dt>
<dd><p>Remove the mapping for object <em>key</em> from the object <em>o</em>. Return <code class="docutils literal"><span class="pre">-1</span></code> on
failure.  This is equivalent to the Python statement <code class="docutils literal"><span class="pre">del</span> <span class="pre">o[key]</span></code>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_HasKeyString">
int <code class="descname">PyMapping_HasKeyString</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em>, const char<em>&nbsp;*key</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_HasKeyString" title="Permalink to this definition">¶</a></dt>
<dd><p>On success, return <code class="docutils literal"><span class="pre">1</span></code> if the mapping object has the key <em>key</em> and <code class="docutils literal"><span class="pre">0</span></code>
otherwise.  This is equivalent to the Python expression <code class="docutils literal"><span class="pre">key</span> <span class="pre">in</span> <span class="pre">o</span></code>.
This function always succeeds.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_HasKey">
int <code class="descname">PyMapping_HasKey</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*key</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_HasKey" title="Permalink to this definition">¶</a></dt>
<dd><p>Return <code class="docutils literal"><span class="pre">1</span></code> if the mapping object has the key <em>key</em> and <code class="docutils literal"><span class="pre">0</span></code> otherwise.  This
is equivalent to the Python expression <code class="docutils literal"><span class="pre">key</span> <span class="pre">in</span> <span class="pre">o</span></code>.  This function always
succeeds.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_Keys">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyMapping_Keys</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_Keys" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>On success, return a list or tuple of the keys in object <em>o</em>.  On failure,
return <em>NULL</em>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_Values">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyMapping_Values</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_Values" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>On success, return a list or tuple of the values in object <em>o</em>.  On failure,
return <em>NULL</em>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_Items">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyMapping_Items</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_Items" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>On success, return a list or tuple of the items in object <em>o</em>, where each item
is a tuple containing a key-value pair.  On failure, return <em>NULL</em>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_GetItemString">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyMapping_GetItemString</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em>, const char<em>&nbsp;*key</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_GetItemString" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Return element of <em>o</em> corresponding to the object <em>key</em> or <em>NULL</em> on failure.
This is the equivalent of the Python expression <code class="docutils literal"><span class="pre">o[key]</span></code>.</p>
</dd></dl>

<dl class="function">
<dt id="c.PyMapping_SetItemString">
int <code class="descname">PyMapping_SetItemString</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*o</em>, const char<em>&nbsp;*key</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em>&nbsp;*v</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyMapping_SetItemString" title="Permalink to this definition">¶</a></dt>
<dd><p>Map the object <em>key</em> to the value <em>v</em> in object <em>o</em>. Returns <code class="docutils literal"><span class="pre">-1</span></code> on failure.
This is the equivalent of the Python statement <code class="docutils literal"><span class="pre">o[key]</span> <span class="pre">=</span> <span class="pre">v</span></code>.</p>
</dd></dl>

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